December 1942. Wearing a German uniform, the former Red Army soldier, Sergeant Alexander Ivanovich Lazarev, voluntarily gives himself up to the Soviet partisans. However, knowing that he had previously defected to the Nazis, Commander Lokotkov and Commissar Petushkov decide to give Lazarev a chance to clear his name, putting his loyalty to the test through a series of operations in Mother Russia's dangerous, snow-covered roads. But, in the end, is Lazarev a traitor or a patriot?